{"title":"The Legacy of Arsenic Contamination from Mining and Processing Refractory Gold Ore at Giant Mine, Yellowknife, Northwest Territories, Canada","authors":"H. Jamieson","doi":"10.2138/RMG.2014.79.12","DOIUrl":null,"url":null,"abstract":"The case of the Giant mine illustrates how a large, long-lived Au mine has resulted in a complex regional legacy of As contamination and an estimated remediation cost of almost one billion Canadian dollars (AANDC 2012). The mine, located a few km north of the city of Yellowknife on the shore of Great Slave Lake (Figs. 1, 2) produced more than 7 million troy ounces of Au (approximately 220 tonnes) from a largely underground operation. Giant mine was the largest producer in the Yellowknife greenstone belt, which produced more than12 million troy ounces (~370 tonnes) in total (Bullen and Robb 2006). Arsenopyrite-bearing Au ore was roasted from 1949 to 1999 as a pretreatment for cyanidation (Fig. 3a). Poor or nonexistent emission controls in the early years resulted in the release of an estimated 20,000 tonnes of roaster-generated As2O3 to the surrounding environment through stack emissions (CPHA 1977; Wrye 2008). Over the lifetime of the mine, however, most of the As2O3 (237,000 tonnes) was stored in underground chambers (Fig. 3b) and is a now an ongoing source of As to groundwater and surface water (INAC 2007; Jamieson et al. 2013). Other roaster products include As-bearing maghemite and hematite (calcine) were deposited with tailings and re-mobilized into creek and lake sediments. Under reducing conditions, post-depositional remobilization of As associated with roaster-generated Fe oxides results in release of As to sediment pore water and reprecipitation of some As as a sulfide phase (Fawcett and Jamieson 2011). However, As(III) in maghemite and As2O3 persists in the oxidizing conditions of near-surface tailings and soils (Walker et al. 2005; Jamieson et al. 2013). Ore roasting increases the solubility, toxicity, and bioaccessibility of As by converting sulfide-hosted As to oxide-hosted As. At Giant, …","PeriodicalId":49624,"journal":{"name":"Reviews in Mineralogy & Geochemistry","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"78","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Reviews in Mineralogy & Geochemistry","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.2138/RMG.2014.79.12","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Earth and Planetary Sciences","Score":null,"Total":0}
引用次数: 78
Abstract
The case of the Giant mine illustrates how a large, long-lived Au mine has resulted in a complex regional legacy of As contamination and an estimated remediation cost of almost one billion Canadian dollars (AANDC 2012). The mine, located a few km north of the city of Yellowknife on the shore of Great Slave Lake (Figs. 1, 2) produced more than 7 million troy ounces of Au (approximately 220 tonnes) from a largely underground operation. Giant mine was the largest producer in the Yellowknife greenstone belt, which produced more than12 million troy ounces (~370 tonnes) in total (Bullen and Robb 2006). Arsenopyrite-bearing Au ore was roasted from 1949 to 1999 as a pretreatment for cyanidation (Fig. 3a). Poor or nonexistent emission controls in the early years resulted in the release of an estimated 20,000 tonnes of roaster-generated As2O3 to the surrounding environment through stack emissions (CPHA 1977; Wrye 2008). Over the lifetime of the mine, however, most of the As2O3 (237,000 tonnes) was stored in underground chambers (Fig. 3b) and is a now an ongoing source of As to groundwater and surface water (INAC 2007; Jamieson et al. 2013). Other roaster products include As-bearing maghemite and hematite (calcine) were deposited with tailings and re-mobilized into creek and lake sediments. Under reducing conditions, post-depositional remobilization of As associated with roaster-generated Fe oxides results in release of As to sediment pore water and reprecipitation of some As as a sulfide phase (Fawcett and Jamieson 2011). However, As(III) in maghemite and As2O3 persists in the oxidizing conditions of near-surface tailings and soils (Walker et al. 2005; Jamieson et al. 2013). Ore roasting increases the solubility, toxicity, and bioaccessibility of As by converting sulfide-hosted As to oxide-hosted As. At Giant, …
Giant金矿的案例说明了一个大型、长寿的金矿如何导致了复杂的砷污染的地区遗产,估计修复成本近10亿加元(AANDC 2012)。该矿位于大奴湖(Great Slave Lake)岸边耶洛奈夫市(Yellowknife)以北几公里处(图1、2),主要是地下开采,生产了700多万金衡盎司(约220吨)的金。Giant矿山是Yellowknife绿石带最大的生产商,总产量超过1200万金衡盎司(约370吨)(bulen and Robb 2006)。从1949年到1999年,作为氰化预处理,对含砷黄铁矿的金矿进行了焙烧(图3a)。在最初的几年里,不良的或不存在的排放控制导致大约20,000吨的焙烧产生的As2O3通过烟囱排放到周围环境中(cfa 1977;Wrye 2008)。然而,在矿山的生命周期内,大部分As2O3(237,000吨)被储存在地下室中(图3b),现在是地下水和地表水的持续As来源(INAC 2007;Jamieson et al. 2013)。其他焙烧产物包括含砷的磁铁矿和赤铁矿(煅烧)与尾矿一起沉积,并重新动员成小溪和湖泊沉积物。在还原条件下,与焙烧产生的铁氧化物相关的砷沉积后再活化导致砷释放到沉积物孔隙水中,并以硫化物相的形式再沉淀一些砷(Fawcett和Jamieson 2011)。然而,磁赤铁矿和As2O3中的As(III)在近地表尾矿和土壤的氧化条件下持续存在(Walker et al. 2005;Jamieson et al. 2013)。矿石焙烧通过将硫化物为主的砷转化为氧化物为主的砷,增加了砷的溶解度、毒性和生物可及性。在巨人公司,……
期刊介绍:
RiMG is a series of multi-authored, soft-bound volumes containing concise reviews of the literature and advances in theoretical and/or applied mineralogy, crystallography, petrology, and geochemistry. The content of each volume consists of fully developed text which can be used for self-study, research, or as a text-book for graduate-level courses. RiMG volumes are typically produced in conjunction with a short course but can also be published without a short course. The series is jointly published by the Mineralogical Society of America (MSA) and the Geochemical Society.